An organic polymer containing a reactive silicon group in the molecule has a property such that even at room temperature the organic polymer is cured into a rubbery state by a reaction with moisture in the air. Among the organic polymers having a reactive silicon group in the molecule, organic polymers in which the main chain skeleton is a polyoxyalkylene polymer are disclosed in (Patent Document 1) and the like. Those polyoxyalkylene polymers have already been industrially produced, and are widely used in applications to sealants, adhesives and the like.
Curable compositions comprising the above described organic polymers are cured by using silanol condensation catalysts, and usually organotin catalysts such as dibutyltin bisacetylacetonate are widely used. However, in recent years, toxicity of organotin compounds is pointed out, and alternative non-tin curing catalysts are desired.
Dealcoholization type silicone compositions using titanium catalysts as a non-organotin catalyst are disclosed in (Patent Document 2), (Patent Document 3) and the like. Those dealcoholization type silicone compositions have already been industrially produced, and are widely used in a variety of applications.
On the other hand, curable compositions prepared by combination use of organic polymers having reactive silicon groups and curing catalysts such as a titanium catalyst, an aluminum catalyst or a zirconium catalyst are disclosed in (Patent Document 4), (Patent Document 5), (Patent Document 6), (Patent Document 7), (Patent Document 8) and the like. SYLYL 5A03 and MS Polymer S303 (both are produced by Kaneka Corporation) are used in examples of (Patent Document 4) and (Patent Document 5), respectively as a reactive silicon group-containing organic polymer. When the compositions of those examples were cured and adhesion thereof was measured, it was found that adhesion to various substrates was inferior and not practical as compared with the case of using, as a catalyst, organotin compounds which are currently used. Also it was found that in the case of using the reactive silicon group-containing organic polymers described in examples of (Patent document 6) and (Patent Document 7), adhesion to various substrates was inferior.
Patent Document 1: JP-52-73998A
Patent Document 2: JP-39-27643B (U.S. Pat. No. 3,175,993)
Patent Document 3: U.S. Pat. No. 3,334,067
Patent Document 4: JP-5-311063A
Patent Document 5: JP-2002-249672A
Patent Document 6: JP-58-17154A (JP-3-57943B)
Patent Document 7: JP-62-146959A (JP-5-45635B)
Patent Document 8: JP-2004-51809A